Many systems exist for conducting tests of microbiological samples for providing patient diagnosis and therapy. It is desirable to use automated systems requiring minimal handling by a technician. At the same time, it is also desirable to utilize systems which provide the most accurate results possible.
Such systems as described above can be used for identification testing wherein it is desirable to determine the identification of any microbes present in a patient's sample. Alternatively, or additionally, it is also desirable to utilize a systems which can be used for susceptibility testing. Susceptibility testing determines the susceptibility of a microbe in a sample to various therapeutics, such as antibiotics.
The U.S. Pat. No. 3,297,873 to Hovnanian discloses a television camera utilized with a control unit in video amplifier, a horizontal line analyzer and a TV monitor. This provides a visual read-out of micro-organisms. The TV monitor displays the specimen or a part of the specimen utilizing a lens and filter combination. Furthermore, a photometer determines the UV absorption or transmission characteristics of micro-organisms, cells or other micro-specimens. The display includes a darkened area, as well as a display of area. The darkened area represents the micro-sampled portion of the specimen.
The U.S. Pat. No. 4,061,469 to DuBose discloses a blood analyzer which utilizes two photodetectors, one as the measuring detector of the sample and the other as a reference detector. The second photodetector senses energy supplied from the source through an individual sample.
The U.S. Pat. No. 4,166,095 to Kling discloses an automatic chemical testing apparatus with visual monitoring and inputting of test results.
The U.S. Pat. No. 4,175,860 to Bacus discloses a method and apparatus for classifying cells, such as red blood cells. The apparatus generates an image that is split into a high resolution and a low resolution image wherein the circuitry performs measurement and analysis relating to the size, density and color of the cytoplasm and the nucleus. The analysis obtained from each of the two images are applied to classification logic circuitry for the purpose of determining malignant cells. The images are obtained from a ridicom camera which are sent to an analog digital converter and to a video monitor. A single slide is used.
The U.S. Pat. No. 4,431,307 to Suovaniemi discloses a particular type of cuvette whose slide walls are provided with a layer of material that prevent measurement of radiation or light directed at the walls for passing through the side walls. The patent discloses that a photo-measurement will be taken of each individual cuvette and the material therein.
The U.S. Pat. No. 4,400,353 to Meseral, etal. discloses an electro-optical system for use in evaluating immunological reactions. Fluid biological test specimens and a reagent are introduced into a reaction zone in an image cell. The reaction cells are formed of two planar surfaces made of glass or plastic material which are provided with a generally circular groove to define the reaction cell. A fill port is pierced in a circular groove for introducing the reagent and the biological fluid. Each image cell is lifted out of its respective compartment and brought into the optical pass sequentially. After transluminating the reaction zone and imaging light being transmitted therethrough on an image sensor, the dark areas formed on the surface of the image sensor are measured by electronics. The image sensor is a charge coupled device (CCD). When several indicator particles agglutinate, the resulting image will shadow several pixels which appear darker than a single particle. The CCD is scanned electronically row by row to obtain each pixel of information. The image areas are quantified electronically and the total area is obtained which is a function of the concentration of the antibody in the wells. The total dark images of the control specimen is related to the respective concentrations. The imaged data is fed to a threshold comparator and particle counter which screens the non-agglutinated particles on the basis of both intensity and particle size.
The U.S. Pat. No. 4,453,266 to Bacus discloses a method and apparatus for measuring cell volume of a red blood cell on a slide. The apparatus includes means for generating signals representative of the area of the cells, and means for measuring the optical density of the individual cells and for generating signals representative of the hemoglobin or massive cells. More than one red blood cell is determined. The image is obtained by a television camera which sends this image to electronics for the analysis. Each of the several cells displayed in the image are independently analyzed.
The U.S. Pat. No. 4,580,895 to Patel discloses a scanning photometer for reading agglutination tests and other procedures by scanning the contents of a micro-test well or other sample holding vessel to determine certain characteristics of the content. The patent discloses scanning an entire tray having a plurality of wells and obtaining a video image across each well. The tray or plate which is utilized has an array of uniformly diametered, upwardly opening sample-holding wells. An XY mover is connected to the holder to move the sensor assembly in a horizontal X-Y coordinate plane to successively bring wells in a preselected order to axial alignment with photodetector. The sensor assembly comprises a photo beam interrupt comb which has a set of parallel and uniformly spaced apart photo beam interrupting teeth arranged in a straight row extending parallel to the motion path of the carriage in X coordinate axis. The assembly also comprises a photo beam interrupt comb which has eight parallel teeth which extend in the Y coordinate axis. The combs cause the production of interrupt signals to the microprocessor to aid in the movement of the tray and designation of each well. The scanning operation is repeated column for column of each of the columns in plate. The photodetector's analog output signal is a measurement of the intensity of the photometers light beam and represents a continuous, traveling measurement of the optical density of the substance in diametrically across each entire well and the optical density of the well bottom. Twenty-four signal samples of the photodetector analog output are digitized periodically such that samples are uniformly spaced apart diametrically across each well. The digital optical density readings of each of the wells are processed by the microcomputer. The photodetector obtains a sample across a diameter of the wells, rather than the entire circle of the well. The microcomputer utilizes a threshold value in a determination of lights and darks of the sample.
The U.S. Pat. No. 4,784,947 to Noeller discloses still photographing a plurality of samples at a single time.
The U.S. Pat. Nos. 4,720,463 and 4,856,073, both to Farber et al. relate to an apparatus and process of automatically obtaining test results from microbiological test rays. In general, microbiological sample and agent to be tested are placed in test rays having a plurality of wells or cupolas. The trays are moved to an incubator for a predetermined time. Thereafter, the trays are moved to an inspection station. A light source is disposed above the tray and a pair of video cameras are disposed below the tray in the inspection station. The video cameras take images of the tray, well by well, and a processor processes the images to analyze the test results. The processor records the background light level of each point or pixel only within the area of interest for each particular well of the tray. For each well, the image processor determines the number of pixels in the area of interest which have an associated voltage exceeding a predetermined threshold for that area of interest. If the number of pixels exceeds a predetermined number, a positive result is assigned to that well. The image processor analyzes the binary partial results from the wells to determine possible identity of the micro-organisms.
The present invention provides a drastic simplification of the prior art apparatus which more accurately identifies and provides a susceptibility testing of a sample. The present invention utilizes a mechanically simple system which utilizes a fluorescent reaction for our identification and susceptibility testing. The fluorescent determinations are faster and much more accurate than prior art determinations due to the high signal to noise ratio of fluorometric systems. Further, an entire tray including a plurality of wells can be imaged simultaneously, not requiring a well by well video inspection. This will increase the speed of inspection, which will provide adequate time for "real time" detection, identification and susceptability analysis.